Pediatric prosthesisPediatric prosthesis
Introduction :
The absence of teeth in children can have various causes, but as in adults, it causes functional and aesthetic problems.
The treatment of toothlessness in children must take into account the particularities of the child, because, during the period of growth, the terrain is constantly changing, the prosthesis must not only restore the function, but also allow normal growth and adequate development of the adult dentition.
Growth:
The maxilla grows at the sutures until 7 years of age, then remodeling by apposition and resorption takes over under the influence of muscles and functions.
The increase in the width of the mandible results from its lengthening associated with the progressive divergence of the hemi-mandibles.
The elongation of the mandible body is under the modeling effect of the musculature and the penetrating matrix (vascular-nervous bundle).
The condyle and its cartilage are the center of mandibular growth in all 3 directions
The alveolar bone conditions the vertical, sagittal and transverse growth of the face.
Causes of missing teeth in children:
The absence or premature loss of teeth can be due to various etiologies:
Local causes
- Traumas
- Caries disease
- Dental anomalies: number anomalies such as anodontia, oligodontia, or hypodontia
General causes:
- General disease causing premature loss of teeth: eg histiocytosis,,,
- Disease requiring extraction: heart disease, chemotherapy, etc.
Consequences of lack of treatment
Functional consequences
- On chewing: Each early tooth loss leads to a decrease in this masticatory coefficient depending on the value of each tooth; any excessive decrease in this coefficient leads to a dietary imbalance, with a soft diet then favored, which can ultimately lead to growth disorders in height and weight.
Efficient mastication is also important for the stimulation of maxillary and mandibular transverse growth; it allows their expansion.
Alternating unilateral chewing is an asymmetrical praxis, that is to say that when a subject chews on the right, this allows the lengthening and widening of the right upper hemimaxilla and the lengthening of the left hemimandible while the right hemimandible thickens in relation to the corpus and the condyle; and vice versa.
- Swallowing: the absence of a group of teeth induces a spreading of the tongue between the edentulous ridges, thus maintaining atypical swallowing
- Phonation: the absence of one or more teeth alters the pronunciation of certain sounds.
- Breathing: In a child with premature loss of several temporary molars, the lower part of the face is reduced and is accompanied by the spreading of the hypertrophied tongue and its repression towards the pharynx, obstructing the upper aerodigestive tract.
This results in mouth breathing at the expense of the nasal cavities, as the tongue is propelled downward and forward to clear the aerodigestive tract.
Mouth breathing leads to stretching of soft tissues influencing craniofacial development towards underdevelopment, lack of stimulation of bony structures, development of a narrow palate, tendency to skeletal class III and tendency to an anterior open bite leading to the formation of a long face syndrome.
It is also notable that the absence of nasal breathing leads to susceptibility to ENT infections.
→ The premature absence of temporary molars therefore increases the risk of developing mouth breathing.
Pediatric prosthesis
Consequences for growth
- The bone bases:
The premature loss of temporary teeth disrupts the various functions which do not perform their stimulating role, leading to more or less significant disorders of local growth depending on the number and location of the missing teeth .
Bilateral mandibular molar edentulation promotes a low lingual position and its spreading.
At the level of the maxilla, insufficient skeletal growth manifested by maxillary hypoplasia (maxillary retrognathia due to maxillary brachygnathia , or maxillary or even mid-level endognathia) may be observed.
In fact, since the tongue is not ideally located, intermaxillary sutural growth is no longer correctly stimulated.
At the level of the mandible, the lower arch is freed from the circumscription constraint of the maxilla; the rate of mandibular growth is then no longer controlled, only certain muscles limit its development, its growth becomes excessive and mandibular prognathism sets in.
This tendency towards mandibular prognathism is amplified by functional progression during opening and closing movements and chewing, linked to the absence of posterior (or even anterior) wedging and the excessive use of the pterygoid muscles.
Without therapeutic management, an anterior rotation of the mandible may be observed, leading to an antero-superior displacement of the chin causing mandibular dysmorphosis leading to a reduction in the lower level of the face and a class III profile.
Alveolar processes:
The alveolar bone is born, lives and disappears with the tooth. The loss of deciduous teeth impairs the chewing function and induces a decrease in bone density and volume.
The different functions guide the growth of the alveolar processes under the action of the muscles; if there is loss of the milk molars, the tongue will interpose itself between the arches and slow down vertical growth.
On maintaining space and eruption
Commonly, premature loss of primary posterior teeth results in:
– A reduction or even loss of the eruption guide of permanent teeth
– A version of the adjacent teeth and an extrusion of the antagonist teeth
. – Crowding, arch asymmetries and deviation of the inter-incisal midpoints. –
A reduction or even loss of arch length → loss of leeway, credit for space existing between the diameters of the temporary molars and canines and between the permanent canines and premolars, the diameters of the temporary molars being greater than those of the premolars.
A disturbance in the eruption of the suction permanent tooth with deviation of the eruption path (ectopia) or even retention of the tooth following the extracted temporary tooth, which can lead to inclusion
– Mesialization of distal teeth at avulsion sites or first permanent molars.
Pediatric prosthesis
Contraindications of pediatric prosthesis
- Age < 2 and a half years
- Uncooperative child
- Poor hygiene
- Lack of cooperation from parents
- Mental deficiency
- Eruption of permanent tooth within 6 months or less
Prosthesis in children
As in adults, prosthetic treatment in children can be removable or fixed, dento- or implant-supported.
The removable partial prosthesis:
It is indicated in temporary, mixed or permanent dentition, has a moderate cost.
A removable prosthesis can be used in children without requiring modification up to the age of 6 years.
- From 6 to 8 years of age, it is advisable to plan for the eruption of the incisors by creating fenestrations in the plate.
- From 9 to 12 years old, provide recesses and jacks, space maintainers
The removable pediatric partial prosthesis is an evolving prosthesis comprising:
- A resin base plate (or non-precious alloy for teenagers)
- Hooks : Simple hooks can be used, and in case of non – retentive anatomy of the teeth, undercuts can be created with composite. Cavalier hooks and Adams hooks are particularly indicated in children because of the low crown height.
- One or more orthodontic devices such as braces when arch expansion is indicated
- Replacement teeth: usually made of resin , and small in size
Realization :
- Clinical examination and case assessment
- Choice of PES + taking alginate impressions
- Casting stone models
- Production of PEI + secondary impressions (possibly)
- Recording of the intermaxillary relationship with restoration of the DV
- Functional test,
- Insertion, balancing
- Periodic checks and corrections
- Note: The jack is included if there is an orthodontic indication,
Pediatric prosthesis
The total removable prosthesis
It is quite rarely indicated, because total edentulism in children is exceptional, it is generally obtained in patients suffering from anhydrotic ectodermal dysplasia syndrome after extraction of the rare teeth whose shape and position prevent the creation of the prosthesis, this is carried out in a classic manner as in adults.
There are, however, difficulties in obtaining satisfactory retention because of the thin and low ridges.
- Periodic corrections must be made to the prosthesis in order to maintain its adaptation
- Prosthesis repair is necessary when the DVO requires augmentation due to growth.
- Retention may be increased if the total prosthesis is supra-dental or supra-radicular (overdenture): dental stumps carrying parallel-walled caps below the prosthetic plate increase friction.
The single fixed prosthesis
It is used on dilapidated primary teeth that must remain on the arch for a fairly long time before being replaced. These are preformed pedodontic caps:
- Metallic: available in several sizes, the metal is malleable enough to allow the cap to be adjusted without preparing the tooth.
- Zirconia: they require prior preparation of the tooth and are sealed using glass ionomer cement
Fixed partial prosthesis
- Rigid connections should be avoided before the end of growth, particularly if the pillars are located on either side of a growth center suture.
- Sometimes, it is necessary to perform composite plastics of the pillars before crowning if the teeth have an atypical conical shape.
Implant prosthesis
- Implant placement is not recommended at an early age because the alveolar bone does not grow around an implant as it does around natural teeth, and the implant-supported prosthesis will become infraccluded at the end of growth.
- However, the symphyseal region is stable very early and can allow the placement of an implant if necessary.
- The maxillary suture stabilizes around 17 years of age, which contraindicates the placement of anterior maxillary implants before adulthood.